For Rep. Darrell Issa, the summer has been much better than the spring.

When he took the helm of the Oversight and Government Reform Committee in January, the California Republican brought expectations that his investigations would reach deep into the White House, forcing large document releases and embarrassing disclosures for Democrats.

Instead, Issa stumbled. At his lowest point, he fired his aggressive spokesman, Kurt Bardella, in a flap over email forwarding. "It was the most difficult week I've had in 10 years of working for Mr. Issa," said Frederick Hill, Issa's communications director.

The committee held a series of mundane hearings. Rob Kelner, a partner at Covington &amp; Burlington who guides clients through Congressional investigations, said "it's been a pretty quiet time" for lawyers like him.

But things started to turn around in the summer, with the panel's ongoing examination of the Bureau of Alcohol, Tobacco, Firearms and Explosives' Project Gunrunner and Operation Fast and Furious.

Although significant chunks of the probe were uncovered by the press, starting with a CBS News expose, Issa kept up the drumbeat, hauling Justice Department officials before the committee to demand answers. Late last month, heads started to roll. The DOJ reassigned ATF acting Director Kenneth Melson. Dennis Burke, the U.S. attorney for Arizona who oversaw the operation, resigned.

The fallout, as well as several other committee moves, have Issa's allies saying he's back on track.

"I think he's hit his stride now," said ex-Rep. Tom Davis (R-Va.), the former chairman of the committee who is a mentor to Issa.

Issa also brought back the controversial Bardella, a move that poses risks but could pay major rewards.

Issa fired Bardella in March for sharing correspondence between himself and other reporters with New York Times reporter Mark Leibovich, who is writing a book about Washington's media wars.

But Bardella is described as bringing political smarts to the communications shop, as well as energy and a close relationship with his boss.

Issa and Bardella "have had a good relationship," Davis said. "That chemistry between staffer and the Member is very important."

Some people in GOP circles question the move, though, six months after Issa said Bardella's actions were "highly inappropriate" and a "breach of trust."

"I don't understand the decision. People know what happened, and there isn't a lot of trust there. I know I wouldn't want a guy like that on my staff," a House Republican aide said.

On Fast and Furious, the program originally came to the public's attention when CBS News published an investigation in February, relying on the accounts of six ATF agents with knowledge of the program.

The agents told CBS that they were ordered to watch guns escape into criminal networks — without any means of tracking them.

Before CBS ran the story, Issa inquired about the program to the Justice Department. In a Feb. 4 letter to Issa and Sen. Chuck Grassley (R-Iowa), the DOJ denied the allegations.

"The allegation described in your January 27 letter — that ATF 'sanctioned' or otherwise knowingly allowed the sale of assault weapons to a straw purchaser who then transported them into Mexico — is false," the letter said.

Since then, Issa's panel has revealed scores of documents and, in a June 15 hearing, heard the testimony of four ATF agents who described orders to allow the straw purchases that had been alleged.

At the most recent hearing on the issue — on July 26 — Issa's foil on the committee, ranking member Elijah Cummings, skeptically demanded answers from a panel of mid-level ATF officials, showing his impatience at times. "Well, that was more than a little bit of extra time, was it not?" the Maryland Democrat asked, pressing about why Fast and Furious wasn't shut down more quickly.

His questioning marked a change in tone. At a June 15 hearing, Cummings apologized to a DOJ witness after a round of angry questioning by Issa.

Ashley Etienne, a spokeswoman for Cummings, said her boss had been "incredibly" consistent on the investigation, pushing to "uncover any wrongdoing" while "ensuring that we don't compromise the ongoing criminal investigation."

Issa suggested there is more to come on Fast and Furious.

"Perhaps within my investigation team, there's a considerable amount of knowledge we have that we're still waiting for them to turn over pursuant to subpoena. That would be reasonable to expect," Issa said last week. "Because, so far, every black redacted page they gave us, virtually, I have the unredacted version first and that's why we asked for it."

Issa also recently scored blows in a fight with the New York Times over a front-page story by reporter Eric Lichtblau.

The four corrections that the paper issue related to the story boosted morale among Issa's nearly 80-member committee staff. "People were coming out of the woodwork. All these people I would have never guessed were writing me to say, 'Wow, the New York Times looks really bad here,'" Hill said.

Democrats say Issa has a long way to go before he can call it a comeback.

His critics highlight investigations dropped without explanation.

The panel had scheduled a July 13 hearing on the Financial Crisis Inquiry Commission, charged with investigating the causes of the financial crisis of 2008.

Issa wondered in a release whether the FCIC and its staff "may have conflicts of interest" preventing an "even-handed investigation." Issa obtained more than 400,000 documents from the commission and scheduled the hearing to grill Democrat Phil Angelides, the chairman of the commission and a former California treasurer.

Angelides had already flown from California to Washington, D.C., when an Issa aide called to tell him the hearing had been postponed.

Angelides' attorney said the aide told him that the panel had found documents that didn't "fit their narrative."

Hill said such an account was "not accurate."

The hearing has not been rescheduled.

A subsequent report from Cummings and his staff revealed embarrassing details about how the Republicans on the FCIC had behaved, illustrating how a probe might be politically inconvenient.

Other investigations are missing in action.

There's an inquiry into VIP loans from Countrywide Financial. "That's a scandal that isn't finished yet," Issa said the night Republicans won the House. Issa subpoenaed documents in February but has made no other public moves.

Issa also said a top concern is whether Freddie Mac and Fannie Mae "should continue existing as they are." The last time the committee addressed the government-sponsored enterprises was when Issa vowed to hold a hearing in January.

On another investigation, into a Government Accountability Office report on for-profit colleges, Issa has not released his findings, despite questions about whether politics interfered with the GAO's report.

Issa admitted they'd been "allowed to slip" and vowed to "do more on those," but he said the committee has had to spend its time wisely.

"We've had to prioritize based on time," he said, adding that Fast and Furious, for instance, was more important.